A C implementation of Spritz, a spongy RC4-like stream cipher and hash function.

int spritz_hash(unsigned char *out, size_t outlen,
                const unsigned char *msg, size_t msglen);

int spritz_stream(unsigned char *out, size_t outlen,
                  const unsigned char *key, size_t keylen);

int spritz_encrypt(unsigned char *out, const unsigned char *msg, size_t msglen,
                   const unsigned char *nonce, size_t noncelen,
                   const unsigned char *key, size_t keylen);

int spritz_decrypt(unsigned char *out, const unsigned char *c, size_t clen,
                   const unsigned char *nonce, size_t noncelen,
                   const unsigned char *key, size_t keylen);

int spritz_auth(unsigned char *out, size_t outlen,
                const unsigned char *msg, size_t msglen,
                const unsigned char *key, size_t keylen);

WARNING You probably shouldn't use Spritz for anything.

It has distinguishers, performance is not impressive (using Spritz for hashing is even slower than Keccak), it depends on conditional jumps and there is no cryptanalysis.